1. Field of the Invention
The invention relates to bearing surfaces in cartilage replacement and total joint replacement.
2. Description of the Related Art
Normal meniscal and articular cartilage have natural properties of compliant conformity with the load bearing bone surfaces. Through unique hydrodynamics, natural cartilage provides a bearing and shock absorbing surface that normally serves an individual for a lifetime. Injury and disease can lead to the need to remove the natural cartilage, and often, the entire joint through an arthroplasty procedure.
Prior art has shown many prosthetic designs and configurations which address the restoration of joint function and biocompatibility. The prior art prosthesis designs either ignore the need for artificial cartilage or, more frequently, address the need with material that provides thickness, strength and a low coefficient of friction. This rigid material has lacked the shock absorbing compliance of natural cartilage and has been ineffective in absorbing the peak contact stresses imposed on a prosthesis when placed in an extreme, load bearing situation.
Repeated exposure to these extreme situations has resulted in particulate wear of the pad and resultant debris. This wear and particulate debris inevitably leads to failure of the prosthesis through pitting and dissolution of the surrounding bony architecture via an inflammatory reaction to the debris. The resultant dissolution of the bony architecture compromises the potential of subsequent prosthetic implantation.
The prior art does not disclose a prosthetic design which provides a lasting replacement for human cartilage or lasting bearing surface for total joint arthroplasty.